The Need for Speed

This endeavour is exploring new vertical-lift capabilities, and is a forerunner to the Future Vertical Lift program that is expected to produce VTOL aircraft that will fly faster and further, carry heavier loads and operate with unmanned systems.

And the historic flight offers a glimpse into the future for Australia, which is understood to have entered into discussions with the US government to join the Future Vertical Lift effort.

The V-280 prototype achieved first flight on December 18 at the Bell Helicopter assembly facility in Amarillo, Texas.

Marketed by the company as promising “more than twice the speed and range of current helicopter platforms”, the V-280 is anticipated to have a cruise speed of 280kt, hence the name.

By way of comparison, the UH‑60M Black Hawk helicopter has a cruise speed of 151 knots and the AH-64E Apache has a maximum level flight speed of more than 150 knots. It remains to be seen whether Bell will be able to achieve double the speed.

Meanwhile, the tiltrotor aircraft’s self-deployable range is listed as 2,100nm or more (without refuelling).

“As we go through 2018, our goal is to demonstrate…the helicopter mode, through conversion to aeroplane mode; showing the speed, showing the range, showing the [hot and high] capability of the aircraft,” Keith Flail, Bell vice-president of advanced tiltrotor systems, told Australian Aviation.

“We have made that commitment to the [US] Army leadership that we intend to exercise and to expand the envelope, so that we can demonstrate all those capabilities; so that they have the most informed position possible for the Future Vertical Lift program as we inform the requirements and continue to reduce risk for the future.”

The V-280 has a footprint that is comparable to that of the UH-60, although it is “a little bit” wider, Flail said. Indeed, observers have noted that the shape of the V-280’s fuselage is similar to that of the Black Hawk.

With a crew of four (two pilots and two crew chiefs), the tiltrotor would be capable of carrying 12 troops, depending on requirements.

Flail expressed confidence that Bell will be able to demonstrate “incredible” agility at both high and low speeds, and described a hypothetical operational scenario to illustrate the point.

Imagine that a V-280 is about four miles from the landing zone (LZ), 100ft up and travelling at 250kt. Within one minute, the tiltrotor would be on the ground and soldiers would be egressing the aircraft through two 1.8m-wide side doors.

And then within about 35 seconds of leaving the LZ and getting back to 100ft, the aircraft would be speeding away at more than 200kt.

‘What that provides to the commander is a huge leap in capability.’ KEITH FLAIL

“If you map that out compared to what a Black Hawk can do, when you want to talk about agility – low-speed agility, high-speed agility, as well as the operational agility; what that provides to the commander – it is a huge leap in capability,” Flail declared.

Lessons learned

The V-280 is regarded as a clean-sheet design, but it leverages lessons learned from the Bell Boeing V-22 Osprey tiltrotor, which famously combines the vertical flight capability of a helicopter with the speed and range of a fixedwing Aircraft.

As a measure of this experience, it was announced in November last year that the V-22 fleet (including the US Marine Corps MV-22 and the US Air Force CV-22) has surpassed a total of 400,000 flight hours.

Sadly, the Osprey’s safety record has been under the spotlight here in Australia after three US marines died when an MV-22B crashed off the coast of the Shoalwater Bay Training Area in Queensland in August.

There are significant design differences between the V-22 and the V-280.

While the entire rotor system and engine/transmission nacelles that are mounted on each wingtip of the Osprey rotate 90 degrees, the Valor’s engines are designed to remain fixed when the next-generation tiltrotor converts from helicopter mode to aeroplane mode for horizontal flight.

Avoiding rotating the GE Aviation T64-GE-419 engines by adopting the fixed engine/rotating proprotor nacelles design is intended to maximise cabin ingress and egress clearance for troops.

“The United States Army, which has the largest vertical-lift fleet on the planet, they have been coming out of side doors of aircraft for air assault operations for decades,” Flail Observed.

“Understanding that customer, how they operate; being able to come in operationally to a landing zone with an aircraft that has twice the speed, twice the range; that element of surprise, speed and survivability.

“To come in, open the side doors, troops come out of the aircraft; no safety issues with main rotors and tail rotors, with the engine in the fixed position and just the props rotating, gives them 7ft of clearance under the wing to come in and out of the aircraft.

“You can put machine guns on the aircraft to provide suppressive fire as you are coming into the LZ. So some of it was for technical reasons, some of it is from the learning from the V-22 experience and some of it is for pure operational reasons.”

And unlike the V-22 with its forward-swept dihedral wing, the V-280 has a simpler straight wing Design.

“We are very focused on design for affordability, design for manufacturing,” Flail said. “How we build that wing significantly gets cost and complexity out.

“We no longer have a mid-wing gearbox over the fuselage, because we do not have the sweep and dihedral in the aircraft.”

The V-280 is being equipped with what is known as the Pilotage Distributed Aperture Sensor, which is a system that will provide 360-degree situational awareness.

This capability would allow pilots and troops alike to ‘see through’ the aircraft structure, offering a view of what is happening on the battlefield Below.

The V-280 will be cyber-hardened, and will support an open system architecture to facilitate hardware and software upgrades.

Speed and range

Bell is not only targeting the US Army; the company envisages the nextgeneration tiltrotor becoming a multiservice, multi-mission aircraft.

An automatic blade-fold/wingstow capability similar to that of the Osprey, which is a key feature of its shipboard compatibility, could be incorporated into the Valor design if Required.

“The V-280 could be used for utility transport operations; it could be configured as an attack aircraft, and also for medevac, especially with the speed and range that we have, what that means in that golden hour if you have wounded troops out there on the battlefield,” Flail said.

The medevac variant might be of particular interest to Australia, given that the 2016 Defence White Paper talked about investigating options to enable the Australian Defence Force (ADF) to undertake combat search and rescue (CSAR) tasks more quickly and at longer ranges.

Defence will explore options for acquiring a long-range aeromedical evacuation and CSAR aircraft that would be capable of operating from the Canberra class amphibious assault ships, according to the Integrated Investment Program that was released with the Defence White Paper.

The capability investment document lists the Long-Range Combat Search and Rescue Aircraft program as having a timeframe of 2023 to 2032.

“Speed and range equate to operational productivity, and give commanders so much more operational flexibility in terms of what they can do,” Flail explained. “You can pick an operation, whatever part of the planet you want to.

“So if you are looking out into the Pacific, where helicopters are extremely challenged because of the limited range that they have and just the geography that they have to deal with, you get so much more capability in the Pacific.

“Look at Africa and the tyranny of distance of all those operations, what speed and range can mean to you.”

Bell is reluctant to comment on any possible acquisition of the V-280 by Australia as any potential sale of its military aircraft would be a government-to-government deal under the Foreign Military Sales (FMS) program.

However, Flail said he understands that Australia, among others, has “expressed interest in a variety of ways” in dialogue with the US Government.

And he raised the possibility that the Future Vertical Lift program could potentially adopt a model along the lines of the F-35 Joint Strike Fighter program, with partner countries joining the effort.

For now, Defence is remaining Tight-lipped.

When asked about a media report stating that Australia has submitted a ‘letter of interest’ regarding participation in the US effort, a spokesperson for Defence simply said Australia “remains interested” in the Joint Multi-Role Technology Demonstration and the Future Vertical Lift program.

Rival design

Sikorsky is partnered with Boeing to develop the SB>1 Defiant helicopter under the Joint Multi-Role Technology Demonstration program.

This demonstrator aircraft design has coaxial counter-rotating rigid main rotor blades and a pusher propeller to enable high-speed acceleration and deceleration.

Lockheed Martin, which owns Sikorsky, says the development of the Defiant will prove the scalability and flexibility of the X2 technology that is also the basis for the S-97 Raider prototype helicopter.

With a crew of four, the Defiant medium-lift helicopter is expected to be capable of carrying 12 troops and their equipment.

First flight for the Defiant had been expected to be achieved in 2017, but this is now due to occur some time this Year.

“Our Defiant aircraft is mostly built,” Randy Rotte, director of business development for cargo helicopter and Future Vertical Lift programs at Boeing, told Australian Aviation.

“We have tested nearly all of our onboard systems, to include hydraulics, engines, fuel systems, electrical systems, avionics and some electronically actuated flight control Surfaces.

“We lack only the delivery of some key components to complete our build.”

Rotte did not specify which components are missing.

However, according to a media report from September last year that quoted US Army Joint Multi-Role Technology Demonstration program director Dan Bailey, the delay in achieving first flight is down to challenges relating to the manufacture of the Defiant’s rotor blades.

The prototype aircraft is being assembled at Sikorsky’s Development Flight Center in West Palm Beach, Florida, where all of the ground and flight testing of the Defiant will be Conducted.

“The Sikorsky/Boeing team is taking a disciplined, risk reduction approach to the SB>1 Defiant program, which will culminate in flight test of the demonstrator,” Rich Koucheravy, business development director for Future Vertical Lift at Sikorsky, told Australian Aviation.

“We plan to fly in 2018 after successful completion of integration testing, ground test, dne [do not exceed limits] establishment and testing on the propulsion system testbed ground test stand.

“We believe this approach will safely lead us to a productive, informative flight test program that will assist the DoD in its objectives.”

Hard landing

As for the Raider program, Sikorsky suffered a setback in August last year when S-97A registration N971SK made a hard landing during a test flight in Florida.

The experimental helicopter sustained “substantial” damage and both pilots suffered minor injuries in the accident, according to a preliminary report issued by the National Transportation Safety Board.

At the time of the hard landing, a second Raider demonstrator was already about 80 per cent built.

“We are in the process of completing that build, and estimate that we will be complete and that we will resume flight testing over the next several months,” Koucheravy said.

The cause of the accident has been identified, Sikorsky says, and changes have been made in an effort to prevent such an incident from happening Again.

“The Raider and Defiant share a common technology base, X2 technology; as a result, we have a process in place to share lessons learned from Sikorsky’s Raider program with the Sikorsky/Boeing team that is working on Defiant,” Koucheravy said.

‘That gives you some innovative new ways to do air operations.’ DR MALCOLM DAVIS

“The cause of that hard landing is unrelated to the X2 technology, but we nonetheless shared that lesson learned with the Defiant team.”

An issue with the flight control system software was to blame, according to media reports quoting Chris Van Buiten, vice-president of Sikorsky Innovations.

Lockheed Martin envisages the Raider light tactical helicopter as carrying six troops and external Weapons.

At the time of an announcement regarding the achievement of its first flight in May 2015, Sikorsky stated that the aircraft’s coaxial rotor/ pusher-propeller design was expected to enable the Raider to hit a cruise speed of up to 240kt.

The predecessor to the Raider, the X2 demonstrator aircraft, clocked up a total of about 22 flight hours before its retirement, having achieved a maximum cruise speed in level flight of 253 knots in September 2010.

A promotional video states that Future Vertical Lift aircraft from Sikorsky and Boeing will be capable of cruise speeds of more than 250 knots.

Thus far, the Sikorsky/Boeing team has not provided the ADF with detailed information about the Defiant helicopter beyond some basic information that has been approved for public release.

However, this situation is expected to change if Australia decides to get involved in the Future Vertical Lift Program.

“We are aware that the US government is discussing potential international cooperation with Australia on the Future Vertical Lift program, and so we look forward to the opportunity to provide the ADF detailed information on Defiant after obtaining the appropriate approvals from the US government,” Rotte said.

“We have expressed our desire to do so to the US government and are beginning the process of obtaining that approval.”

Rotte added that Boeing and Sikorsky are confident the Defiant would be suitable for use by the ADF, and declared that detailed discussions would demonstrate this.

“The US and Australia share much in common about the way they use vertical-lift aircraft to support military operations, and the two countries place a great emphasis on interoperability,” the Boeing spokesperson noted.

Transition platform

Although any potential acquisition of Future Vertical Lift aircraft by Australia may be some way off, the decision on replacing the Tiger ARH attack helicopter will be a key factor in determining the path that the Australian Army follows.

That is the view of Dr Malcolm Davis, senior analyst in defence strategy and capability at the Australian Strategic Policy Institute (ASPI).

Dr Davis told Australian Aviation that he understands the Tiger replacement, which is to be introduced from the mid-2020s, is envisaged as a “transition platform” that would pave the way for a Future Vertical Lift capability for Australia in the late 2030s.

Australia will likely acquire the Boeing AH-64E Apache ‘Echo’ to replace the Tiger (subject to funding and capability requirements), the ASPI analyst said.

“Whatever we get in the next step to replace the Aussie Tiger will determine probably where we go in the following step with the Future Vertical Lift side of things,” he said.

“Decisions that are made over the next few years about replacing the Aussie Tiger I think are going to be fairly influential in deciding what is the future down the track in the 2030s and beyond.”

As the Integrated Investment Program states, the future Armed Reconnaissance Helicopter Replacement capability that will succeed the Tiger could involve manned or unmanned systems, or a combination of both.

Dr Davis anticipates the US Marine Corps being the first adopter of the V-280 Valor, rather than the US Army, and sees the tiltrotor as a suitable option for Australia. “The V-280 obviously would give Australia a high-speed troop-carrying capability,” he said.

“You could attach weapons pods to it, so it gives it an armed troopcarrying capability, which would be very useful.

“And so in terms of tactical mobility across the battlespace, the V-280 is obviously a good option.”

The troop-carrying Valor aircraft could be escorted by Bell’s unmanned V-247 Vigilant tiltrotor, he added.

“That gives you some innovative new ways to do air operations across the battlespace, because you can exploit speed, manoeuvrability, surprise and so forth, which you cannot really exploit with traditional rotary-wing platforms like Chinook, for example, or the Black Hawk,” Dr Davis said.

“You have got greater range, you have got greater speed, you have got greater manoeuvrability, and you have that potential for a mannedunmanned teaming that is really important, not only for the Future Vertical Lift but also for the nextgeneration platform, like Apache Echo.”

However, when considering the acquisition of new types of aircraft, it is not just a matter of weighing up the pros and cons of a particular platform and assessing the costs involved.

“There is that cultural resistance that militaries have to get through – and it is happening in the US military as well; there is a degree of cultural resistance to unmanned combat air vehicles, for example – that I think you have to think about when you are looking at these procurement decisions,” Dr Davis observed.

An armed service must be ready to embrace the introduction of a new sort of capability for the first time; in this case, tiltrotor aircraft.

“When the V-22 came out there was a great deal of resistance and we did not go down that path,” the ASPI analyst said.

“Now that the tiltrotor concept has matured a bit, and I think is starting to show its advantages, will [the Australian] Army take that path more easily in the future?

“It is possible that you could see with that combat search and rescue requirement that they do go down the tiltrotor path, and then that leads them to a V-280, V-247 platform choice in the 2030s.”

Rather than settling on just one type of aircraft design for all missions, it is likely the US Army will end up with a mix of tiltrotor and coaxial aircraft.

And it will be fascinating to see what path the ADF takes in the coming years.